JPH09157245A - New phenolsulfonic ester and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound useful as an acid generator in positive-type photoresist materials for high energy beams excellent in sensitivity and resolution. SOLUTION: This new compound is a phenolsulfonic ester of formula I [R1 -R5 are each H, a halogen, a (substituted) straight-chain or branched alkyl, alkoxyl or alkenyl; R6 is a (substituted) alkyl or aryl; (m) and (n) are each 1 or 2] which is obtained by dehydrochlorination between a phenolic compound of formula II [e.g. 1,3,3-trimethyl-1-(4-hydroxyphenyl)-indan-6-ol, 1,3,3,5- tetramethyl-1-(3-methyl-4-hydroxyphenyl-indan-6-ol] and the corresponding sulfonic acid chloride.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel phenolsulfonic acid ester and a resist material containing the same. Particularly, in a positive photoresist material that generates an acidic substance at the time of exposure to decompose the dissolution inhibitor of the photoresist and make the exposed portion soluble in an alkaline developer, the phenol sulfonate is used as an acid generator. The present invention relates to a positive photoresist material suitable for fine processing.

[0002]

2. Description of the Related Art Conventionally, with the high integration and high density of LSIs (high-density integrated circuits), miniaturization of pattern rules has been demanded, but light emitted from a light source used in a normal optical exposure technique. Has a long wavelength and is not a single wavelength, so there is a limit to the miniaturization of the pattern rule. Therefore, g-line (wavelength 436 nm) or i emitted from the ultra-high pressure mercury lamp
The use of a line (wavelength 365 nm) as a light source has also been considered. However, even in these cases, the resolution of the pattern rule is limited to about 0.5 μm, and the LSI that can be manufactured by this is only the integration degree of about 16 Mbit DRAM. Therefore, in recent years, far-ultraviolet lithography, which has a shorter wavelength than g-line and i-line, is regarded as promising. It is also possible to form a pattern rule of 0.1 to 0.3 μm by using deep-UV lithography, and when a resist material having low light absorption is used, a sidewall that is almost vertical to the substrate is formed. It is possible to form patterns that have. Furthermore, it is also possible to transfer patterns at one time, which is superior to lithography using electron beams in that the pattern formation processing efficiency (throughput) is higher. Further, since it becomes possible to use a KrF excimer laser having a high luminous intensity as a light source for far-ultraviolet rays, a resist material having a particularly small absorbance and a high sensitivity is used from the viewpoint of mass-producing an LSI using various light sources. Is required.

[0003] In response to such requirements, a chemically amplified resist material which has a sensitivity equal to or higher than that of a conventional high-sensitivity resist material and has high resolution and dry etching resistance and which is produced by using an acid as a catalyst has been developed. (For example, Liu et al., Journal of Vacuum Science and Technology (Liu, et. Al., J. Vac.S.
ci. Techno. B6, 379 (1988))], Novolak resin, melamine compound and acid generator by Shipley Co.
A chemically amplified negative resist material (brand name SAL601ER7) consisting of the components has already been commercialized. But LS
When a negative resist material is used in the manufacturing process of I, it is easy to form wirings and gate portions, but it is difficult to form contact holes that require fine processing. Moreover, when the conventionally proposed chemically amplified positive type resist material is used as it is for pattern formation by deep ultraviolet rays, electron beams or X-rays, the solubility of the resist surface is lowered and the pattern after development is over. Since it tends to be hung, it becomes difficult to control the pattern size, not only impairing dimensional controllability during substrate processing by dry etching,
There is a drawback that it tends to cause the pattern to collapse [eg,
KG Chiong, et. Al., J. Vac. Sci. Techno. B7, 1
771 (1989)].

At present, there is a strong demand for the development of a chemically amplified positive resist material that solves the above problems. In response to such a demand, a chemically amplified positive resist material has been proposed in which an onium salt is added to a poly (butoxycarbonyloxystyrene) resin in which a hydroxyl group of a poly (hydroxystyrene) derivative is protected by a tert-butoxycarbonyl group. [For example, Ito, et.al., Polymers in Electoro
nics, ACS Synposium Series, 242, 11 (1984)]. However, the above-mentioned onium salt contains antimony as a metal component, and when a resist material containing the onium salt is used, not only is the substrate contaminated, but the resist material ages after irradiation with deep ultraviolet rays and the like. The problem is that the change is extremely large.

Further, a positive type resist material for deep ultraviolet rays, which comprises a poly (p-styreneoxytetrahydropyranyl) resin as a main component and an acid generator added thereto, has been proposed (Ueno et al., 36th session). Japan Society of Applied Physics
1989, 1p-k-7). However, the above-mentioned positive resist material has a drawback that it is easy to reverse from a positive type to a negative type with respect to deep ultraviolet rays, electron beams or X-rays. 2 consisting of a resin in which the above hydroxyl group is protected with a protecting group and an acid generator 2
Component type positive resist materials are required to decompose many protecting groups in order to be dissolved in a developing solution.
There are problems that the film thickness of the resist is changed in the manufacturing process, and stress and bubbles are easily generated in the film.

As a chemically amplified positive resist material that overcomes the problems of the above-described two-component positive resist material, a three-component positive resist material comprising an alkali-soluble resin, a dissolution inhibitor and an acid generator is used. Is being developed. As a three-component positive resist material, a resist material containing a novolak resin, an acetal compound as a dissolution inhibitor, and an acid generator (RAY / Hoechst)
Have been developed for X-ray lithography. However, since the resist material undergoes chemical amplification at room temperature, its resist sensitivity greatly depends on the time from X-ray exposure to development. Therefore, since it is necessary to control the time very strictly, it is difficult to stabilize the dimension of the pattern, and the absorption of the KrF excimer laser (wavelength 248 nm) is large, and the laser is used. It is unsuitable for lithographic use.

Most of the compounds having a tert-butoxycarbonyloxy group have the effect of inhibiting the solubility of the novolak resin, that is, the tert-butoxycarbonyloxy group has the effect of inhibiting the dissolution of the novolak resin. It has been known. From such a viewpoint, a three-component positive resist material composed of a novolak resin, a dissolution inhibitor in which a tert-butoxycarbonyl group is introduced into bisphenol A, and pyrogallol methanesulfonic acid ester has been proposed [Schlegel et al., 19
90th Spring, 37th Joint Lecture Meeting of Japan Society of Applied Physics, 2
8p-ZE-4]. However, it is difficult to put this system into practical use because the novolak resin absorbs a large amount of light.

Generally, when chemical amplification is performed, heat treatment is often required after exposure. In this case, although the number of steps is increased as compared with a resist material that is chemically amplified at room temperature, it is not necessary to strictly control the time from exposure to development, so that the resist characteristics are stable.
In addition, in a three-component chemically amplified positive resist composition comprising a resin, a dissolution inhibitor and an acid generator, the dissolution inhibitor controls the dissolution rate of the resist film in an alkali developer [(high energy ray (Dissolution rate of the part irradiated with) / (dissolution rate of non-irradiated part)
It is known that (increasing the dissolution rate ratio)] has a great influence on the performance as a resist material. For this purpose, the dissolution inhibitor in the resist film portion when irradiated with high energy rays such as ultraviolet rays is rapidly decomposed, and an acidic substance is generated to change it to a substance that dissolves in an alkaline developer. Therefore, it is important to develop acid generators.

[0009]

An object of the present invention is to provide a high-sensitivity and high-resolution positive photoresist material for high-energy rays, and to develop an excellent acid generator for that purpose. Is.

[0010]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that certain phenol sulfonates have excellent performance,
The present invention has been completed. That is, the present invention relates to a phenol sulfonic acid ester represented by the following general formula (1) (Chemical formula 2), in a positive photoresist material containing an alkali-soluble resin, a dissolution inhibitor and an acid generator, The present invention relates to a positive photoresist material containing a phenolsulfonic acid ester represented by the general formula (1) as the acid generator.

[0011]

Embedded image (In the formula, R _{1 to} R ₅ each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group which may have a substituent, an alkoxy group or an alkenyl group;
₆ represents an optionally substituted alkyl group or aryl group, and m and n represent 1 or 2. )

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The phenol sulfonate represented by the general formula (1) of the present invention is a novel compound.
In the phenol sulfonate represented by the general formula (1), R _{1 to} R ₅ are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group which may have a substituent, or an alkoxy group. Or it is an alkenyl group.
Preferably, a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or 2 to 20 carbon atoms. And more preferably a hydrogen atom, chlorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group,
It is a tert-butyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a tert-butoxy group or an allyl group. Particularly preferably, R ₂ is a hydrogen atom.

In the phenol sulfonic acid ester represented by the general formula (1), R ₆ is an optionally substituted alkyl group or an optionally substituted aryl group. Esters, alkanesulfonic acid esters such as ethanesulfonic acid ester, perfluoroalkanesulfonic acid esters such as trifluoromethanesulfonic acid ester, pentafluoroethanesulfonic acid ester, benzenesulfonic acid ester, p-toluenesulfonic acid ester, etc. And aromatic sulfonates. Further, in the phenolsulfonic acid ester represented by the general formula (1), m, n
Is 1 or 2, preferably 1. In the phenol sulfonate represented by the general formula (1) of the present invention, the hydroxyl group of the phenols (hereinafter, referred to as CDs) represented by the following formula (2) (Chemical formula 3) is sulfonate esterified. And is a compound containing two or more esters. The number of esters is preferably two, and specifically, sulfonic acid esters derived from the following CDs.

[0014]

Embedded image (In the formula, R _{1 to} R ₅ , m and n are the same as above.)

In the following, specific examples of the CDs to be converted into the sulfonic acid ester in the present invention are shown, but the present invention is not limited to these. Exemplary compound 1. 1,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol, 1. 1,3,3,5-tetramethyl-1- (4-hydroxyphenyl) -indan-6-ol, 3. 3. 1,3,3,5,7-pentamethyl-1- (4-hydroxyphenyl) -indan-6-ol, 4. 1,3,3,7-Tetramethyl-1- (4-hydroxyphenyl) -indan-6-ol, 1,3,3,7-tetramethyl-1- (3-methyl-4
-Hydroxyphenyl) -indan-6-ol, 6. 1.3,3,7-Tetramethyl-1- (3,5-dimethyl-4-hydroxyphenyl) -indan-6-ol 7. 1,3,3-Trimethyl-1- (3-methyl-4-hydroxyphenyl) -indan-6-ol 8. 1,3,3,5-tetramethyl-1- (3-methyl-4
-Hydroxyphenyl) -indan-6-ol 9. 1,3,3,5,7-pentamethyl-1- (3-methyl-
4-hydroxyphenyl) -indan-6-ol 10. 1,3,3-trimethyl-1- (3,5-dimethyl-
4-hydroxyphenyl) -indan-6-ol

11. 1,3,3,5-tetramethyl-1-
(3,5-Dimethyl-4-hydroxyphenyl) -indan-6-ol 12. 13.3,3,5,7-Pentamethyl-1- (3,5-dimethyl-4-hydroxyphenyl) -indan-6-ol 13. 1,3,3-Trimethyl-1- (4-hydroxyphenyl) -indan-5-ol 14. 1,3,3,6-tetramethyl-1- (4-hydroxyphenyl) -indan-5-ol 15. 1,3,3,6,7-pentamethyl-1- (4-hydroxyphenyl) -indan-5-ol 16. 1,3,3,7-tetramethyl-1- (4-hydroxyphenyl) -indan-5-ol 17. 1,3,3,7-tetramethyl-1- (3-methyl-
4-hydroxyphenyl) -indan-5-ol 18. 1,3,3,7-tetramethyl-1- (3,5-dimethyl-4-hydroxyphenyl) -indan-5-ol 19. 1,3,3-trimethyl-1- (3-methyl-4-
Hydroxyphenyl) -indan-5-ol 20. 1,3,3,6-tetramethyl-1- (3-methyl-
4-hydroxyphenyl) -indan-5-ol

21. 1,3,3,6,7-pentamethyl-1-
(3-Methyl-4-hydroxyphenyl) -indane-
5-all 22. 1,3,3-trimethyl-1- (3,5-dimethyl-
4-hydroxyphenyl) -indan-5-ol 23. 1,3,3,6-tetramethyl-1- (3,5-dimethyl-4-hydroxyphenyl) -indan-5-ol 24. 1,3,3,6,7-pentamethyl-1- (3,5-dimethyl-4-hydroxyphenyl) -indan-5-ol 25. 1,3,3-trimethyl-1- (3-hydroxyphenyl) -indan-6-ol 26. 1,3,3,5-tetramethyl-1- (3-hydroxyphenyl) -indan-6-ol 27. 1,3,3,5,7-pentamethyl-1- (3-hydroxyphenyl) -indan-6-ol 28. 1,3,3,7-tetramethyl-1- (3-hydroxyphenyl) -indan-6-ol 29. 1,3,3-trimethyl-1- (3-hydroxyphenyl) -indan-7-ol 30. 1,3,3,5-Tetramethyl-1- (3-hydroxyphenyl) -indan-7-ol

31. 1,3,3,5,7-pentamethyl-1-
(3-Hydroxyphenyl) -indan-7-ol 32. 1,3,3,7-tetramethyl-1- (3-hydroxyphenyl) -indan-7-ol 33. 1,3,3-trimethyl-5-ethyl-1- (4-
Hydroxyphenyl) -indan-6-ol 34. 1,3,3-trimethyl-5-isopropyl-1-
(4-Hydroxyphenyl) -indan-6-ol 35. 1,3,3-trimethyl-5-methoxy-1- (4
-Hydroxyphenyl) -indan-6-ol 36. 1,3,3-trimethyl-5-ethoxy-1- (4
-Hydroxyphenyl) -indan-6-ol 37. 1,3,3-trimethyl-5-propyl-1- (4
-Hydroxyphenyl) -indan-6-ol 38. 1,3,3-Trimethyl-5-t-butyl-1-
(4-Hydroxyphenyl) -indan-6-ol 39. 1,3,3-trimethyl-5-propoxy-1-
(4-Hydroxyphenyl) -indan-6-ol 40. 1,3,3-Trimethyl-5-chloro-1- (4-
Hydroxyphenyl) -indan-6-ol

41. 1,3,3-Trimethyl-5-butoxy-1- (4-hydroxyphenyl) -indane-6-
All 42. 1,3,3-trimethyl-5-isopropoxy-1
-(4-Hydroxyphenyl) -indan-6-ol 43. 1,3,3-Trimethyl-5-isobutyl-1-
(4-Hydroxyphenyl) -indan-6-ol 44. 1,3,3-trimethyl-5-n-butyl-1-
(4-Hydroxyphenyl) -indan-6-ol 45. 1,3,3-trimethyl-5-allyl-1- (4-
Hydroxyphenyl) -indan-6-ol 46. 1,3,3-trimethyl-5-hydroxy-1-
(4-Hydroxyphenyl) -indan-6-ol 47. 1,3,3-Trimethyl-7-ethyl-1- (4-
Hydroxyphenyl) -indan-6-ol 48. 1,3,3-Trimethyl-7-isopropyl-1-
(4-Hydroxyphenyl) -indan-6-ol 49. 1,3,3-trimethyl-7-methoxy-1- (4
-Hydroxyphenyl) -indan-6-ol 50. 1,3,3-trimethyl-7-ethoxy-1- (4
-Hydroxyphenyl) -indan-6-ol

51. 1,3,3-Trimethyl-7-propyl-1- (4-hydroxyphenyl) -indane-6-
All 52. 1,3,3-Trimethyl-7-t-butyl-1-
(4-Hydroxyphenyl) -indan-6-ol 53. 1,3,3-trimethyl-7-propoxy-1-
(4-Hydroxyphenyl) -indan-6-ol 54. 1,3,3-Trimethyl-7-chloro-1- (4-
Hydroxyphenyl) -indan-6-ol 55. 1,3,3-Trimethyl-7-butoxy-1- (4
-Hydroxyphenyl) -indan-6-ol 56. 1,3,3-trimethyl-7-isopropoxy-1
-(4-Hydroxyphenyl) -indan-6-ol 57. 1,3,3-Trimethyl-7-isobutyl-1-
(4-Hydroxyphenyl) -indan-6-ol 58. 1,3,3-Trimethyl-7-n-butyl-1-
(4-Hydroxyphenyl) -indan-6-ol 59. 1,3,3-Trimethyl-7-allyl-1- (4-
Hydroxyphenyl) -indan-6-ol 60. 1,3,3-trimethyl-7-hydroxy-1-
(4-Hydroxyphenyl) -indan-6-ol

61. 1,3,3-trimethyl-8-ethyl-1- (4-hydroxyphenyl) -indan-6-ol 62. 1,3,3-Trimethyl-8-isopropyl-1-
(4-Hydroxyphenyl) -indan-6-ol 63. 1,3,3-trimethyl-8-methoxy-1- (4
-Hydroxyphenyl) -indan-6-ol 64. 1,3,3-trimethyl-8-ethoxy-1- (4
-Hydroxyphenyl) -indan-6-ol 65. 1,3,3-trimethyl-8-propyl-1- (4
-Hydroxyphenyl) -indan-6-ol 66. 1,3,3-Trimethyl-8-t-butyl-1-
(4-Hydroxyphenyl) -indan-6-ol 67. 1,3,3-trimethyl-8-propoxy-1-
(4-Hydroxyphenyl) -indan-6-ol 68. 1,3,3-Trimethyl-8-chloro-1- (4-
Hydroxyphenyl) -indan-6-ol 69. 1,3,3-Trimethyl-8-butoxy-1- (4
-Hydroxyphenyl) -indan-6-ol 70. 1,3,3-Trimethyl-8-isopropoxy-1
-(4-Hydroxyphenyl) -indan-6-ol

71. 1,3,3-Trimethyl-8-isobutyl-1- (4-hydroxyphenyl) -indane-6
-All 72. 1,3,3-Trimethyl-8-n-butyl-1-
(4-Hydroxyphenyl) -indan-6-ol 73. 1,3,3-trimethyl-8-allyl-1- (4-
Hydroxyphenyl) -indan-6-ol 74. 1,3,3-trimethyl-8-hydroxy-1-
(4-Hydroxyphenyl) -indan-6-ol 75. 1,3,3-trimethyl-7-ethyl-1- (3-
Ethyl-4-hydroxyphenyl) -indan-6-ol 76. 1,3,3-Trimethyl-7-allyl-1- (3-
Allyl-4-hydroxyphenyl) -indan-6-ol 77. 1,3,3-Trimethyl-7-isopropyl-1-
(3-Isopropyl-4-hydroxyphenyl) -indan-6-ol 78. 1,3,3-trimethyl-7-methoxy-1- (3
-Methoxy-4-hydroxyphenyl) -indane-6
-All 79. 1,3,3-trimethyl-7-ethoxy-1- (3
-Ethoxy-4-hydroxyphenyl) -indane-6
-All 80. 1,3,3-trimethyl-7-propyl-1- (3
-Propyl-4-hydroxyphenyl) -indane-6
-All

81. 1,3,3-Trimethyl-7-t-butyl-1- (3-t-butyl-4-hydroxyphenyl) -indan-6-ol 82. 1,3,3-trimethyl-7-propoxy-1-
(3-propoxy-4-hydroxyphenyl) -indan-6-ol 83. 1,3,3-Trimethyl-7-chloro-1- (3-
Chlor-4-hydroxyphenyl) -indan-6-ol 84. 1,3,3-Trimethyl-7-butoxy-1- (3
-T-butoxy-4-hydroxyphenyl) -indan-6-ol 85. 1,3,3-trimethyl-7-isopropoxy-1
-(3-isopropoxy-4-hydroxyphenyl)-
Indane-6-all 86. 1,3,3-Trimethyl-7-isobutyl-1-
(3-Isobutyl-4-hydroxyphenyl) -indan-6-ol 87. 1,3,3-Trimethyl-7-n-butyl-1-
(3-n-Butyl-4-hydroxyphenyl) -indan-6-ol 88. 1,3,3-Trimethyl-7-allyl-1- (3-
Allyl-4-hydroxyphenyl) -indan-6-ol 89. 1,3,3-trimethyl-7-hydroxy-1-
(3-Hydroxy-4-hydroxyphenyl) -indan-6-ol 90. 1,3,3-trimethyl-5-ethyl-1- (3-
Hydroxyphenyl) -indan-6-ol

91. 1,3,3-Trimethyl-5-isopropyl-1- (3-hydroxyphenyl) -indane-
6-all 92. 1,3,3-trimethyl-5-methoxy-1- (3
-Hydroxyphenyl) -indan-6-ol 93. 1,3,3-trimethyl-5-ethoxy-1- (3
-Hydroxyphenyl) -indan-6-ol 94. 1,3,3-trimethyl-5-propyl-1- (3
-Hydroxyphenyl) -indan-6-ol 95. 1,3,3-Trimethyl-5-t-butyl-1-
(3-Hydroxyphenyl) -indan-6-ol 96. 1,3,3-trimethyl-5-propoxy-1-
(3-Hydroxyphenyl) -indan-6-ol 97. 1,3,3-Trimethyl-5-chloro-1- (3-
Hydroxyphenyl) -indan-6-ol 98. 1,3,3-trimethyl-5-butoxy-1- (3
-Hydroxyphenyl) -indan-6-ol 99. 1,3,3-trimethyl-5-isopropoxy-1
-(3-Hydroxyphenyl) -indan-6-ol 100. 1,3,3-Trimethyl-5-isobutyl-1-
(3-Hydroxyphenyl) -indan-6-ol

101. 1,3,3-trimethyl-5-n-
Butyl-1- (3-hydroxyphenyl) -indane-
6-all 102. 1,3,3-trimethyl-5-allyl-1- (3
-Hydroxyphenyl) -indan-6-ol 103. 1,3,3-trimethyl-5-hydroxy-1-
(3-Hydroxyphenyl) -indan-6-ol 104. 1,3,3-trimethyl-5-ethyl-1- (3
-Hydroxyphenyl) -indan-7-ol 105. 1,3,3-trimethyl-5-isopropyl-1
-(3-Hydroxyphenyl) -indan-7-ol 106. 1,3,3-trimethyl-5-methoxy-1-
(3-Hydroxyphenyl) -indan-7-ol 107. 1,3,3-trimethyl-5-ethoxy-1-
(3-Hydroxyphenyl) -indan-7-ol 108. 1,3,3-trimethyl-5-propyl-1-
(3-Hydroxyphenyl) -indan-7-ol 109. 1,3,3-Trimethyl-5-t-butyl-1-
(3-Hydroxyphenyl) -indan-7-ol 110. 1,3,3-trimethyl-5-propoxy-1-
(3-Hydroxyphenyl) -indan-7-ol

111. 1,3,3-Trimethyl-5-chloro-1- (3-hydroxyphenyl) -indane-7-
All 112. 1,3,3-Trimethyl-5-butoxy-1-
(3-Hydroxyphenyl) -indan-7-ol 113. 1,3,3-trimethyl-5-isopropoxy-
1- (3-hydroxyphenyl) -indan-7-ol 114. 1,3,3-Trimethyl-5-isobutyl-1-
(3-Hydroxyphenyl) -indan-7-ol 115. 1,3,3-trimethyl-5-n-butyl-1-
(3-Hydroxyphenyl) -indan-7-ol 116. 1,3,3-trimethyl-5-allyl-1- (3
-Hydroxyphenyl) -indan-7-ol 117. 1,3,3-trimethyl-5-hydroxy-1-
(3-hydroxyphenyl) -indan-7-ol and the like can be mentioned. Among them, preferred compounds are 1,
3,3-Trimethyl-1- (4-hydroxyphenyl)-
Indane-6-ol.

The phenolic ester represented by the general formula (1) is synthesized according to a known method for producing a sulfonic acid ester. For example, it can be obtained by dehydrochlorinating the CDs and the corresponding sulfonic acid chloride. At this time, it is preferable to carry out in the presence of a base as a hydrochloric acid scavenger, particularly an organic base such as triethylamine or pyridine. The amount used may be equivalent to or more than the generated hydrochloric acid, but a small excess, specifically 1 to 2 equivalents, more preferably 1.1 to 1 due to volumetric efficiency during the reaction and complexity of post-treatment. Used in the range of 1.5 equivalents.

At this time, the reaction between the sulfonic acid chlorides and the CDs is generally an exothermic reaction, so it is desirable to proceed with the reaction while dropping any one of them. In general, it is desirable to drop CDs, but it is not particularly limited. The amount of sulfonic acid chloride used in the reaction is 1 equivalent or more, preferably 1.1
It is used in the range of 3 to 3 equivalents, more preferably 1.1 to 1.5 equivalents. At this time, it is desirable to use a solvent that does not participate in the reaction in order to make the reaction system uniform and facilitate the dropping of CDs or sulfonic acid chloride. Specific examples thereof include halogen solvents such as dichloromethane, dichloroethane and chloroform, aromatic solvents such as benzene, toluene and chlorobenzene, and ketone solvents such as acetone and methyl ethyl ketone. Of course, an organic base such as triethylamine or pyridine may be used as the solvent.

The reaction temperature is preferably -10 ° C to the boiling point of the reaction solvent, more preferably 0 ° C to the boiling point of the reaction solvent, and most preferably 5 ° C to 50 ° C. Although the reaction time depends on the reaction temperature, it is substantially until the starting CDs are not detected, and the reaction is generally completed in about 10 minutes to 10 hours. After the completion of the reaction, it is necessary to sufficiently wash the produced hydrochloride of the organic amine, a small excess amount of the organic base, and sulfonic acid chloride with diluted hydrochloric acid and neutral water. As described above, the CDs can be converted into the corresponding sulfonic acid ester.

The phenolsulfonic acid ester produced by this reaction can be obtained in sufficiently high purity. However, purification to a higher degree of purity is preferable for using the phenol sulfonic acid ester as the photoresist material of the present invention. The phenolsulfonic acid ester can be further purified by a known method (eg, column chromatography, recrystallization, solvent sludge, etc.). It was revealed that the phenol sulfonate represented by the general formula (1) thus obtained has excellent performance as an acid generator for a positive photoresist material.

The positive photoresist material of the present invention contains an alkali-soluble resin, a dissolution inhibitor and an acid generator, and can be developed with an aqueous alkali solution after irradiation.
A positive photoresist material sensitive to high energy, which is a positive photoresist material containing a phenolsulfonic acid ester represented by the general formula (1) as the acid generator, and a known resist material as described later. Further, various known formulations for producing the can be applied.

The alkali-soluble resin has a small absorption in the vicinity of the exposure wavelength, that is, in the vicinity of 248 nm of KrF excimer laser to 365 nm of the i-line, preferably in the single wavelength region. , Preferably a poly (hydroxystyrene) derivative. Preferred poly (hydroxystyrene) derivatives are poly (hydroxystyrene) resins, hydrogenated (polyhydroxystyrene) resins, poly (hydroxystyrene) resins in which some of the hydrogen atoms of the hydroxyl groups are replaced with tert-butoxycarbonyl groups, Hydrogenated poly (hydroxystyrene) resin in which some hydrogen atoms of hydroxyl groups are replaced with tert-butoxycarbonyl groups, poly (hydroxystyrene) resin in which some hydrogen atoms of hydroxyl groups are replaced with tetrahydropyranyl groups, Hydrogenated poly (hydroxystyrene) resin in which some hydrogen atoms of the hydroxyl groups have been replaced with tetrahydropyranyl groups, a copolymer of hydroxystyrene and styrene, and some of the hydrogen atoms of the hydroxyl groups have been replaced with tert-butoxycarbonyl groups. A copolymer of hydroxystyrene and styrene Beauty hydrogen atoms of some hydroxyl groups can be exemplified a copolymer consisting of styrene and hydroxystyrene substituted tetrahydropyranyl group. These resins may be used alone or in combination of two or more.

Further, as the alkali-soluble resin for the photoresist material of the present invention, in addition to the above-mentioned poly (hydroxystyrene) derivative, novolac type resin, phenol aralkyl resin, naphthol aralkyl resin, phenol and dicyclopentadiene are further included. It is also possible to use an alkali-soluble resin such as a copolymer, polymethylmethacrylate, and a copolymer of styrene and maleic anhydride together. The content of the alkali-soluble resin in the photoresist material of the present invention is preferably 45 to 90% by weight, more preferably 60 to 89% by weight, and particularly preferably 72 to 87%.

Hereinafter, as preferred examples of the alkali-soluble resin, a poly (hydroxystyrene) derivative and a poly (hydroxystyrene) derivative in which hydrogen atoms of some hydroxyl groups are tert-butoxycarbonylated will be described in detail. Among the alkali-soluble resins according to the present invention, as a poly (hydroxystyrene) derivative in which hydrogen atoms of some hydroxyl groups are tert-butoxycarbonylated,
The ert-butoxycarbonylation rate is preferably in the range of 10 to 80%, more preferably 20 to 70%. t
If the ert-butoxycarbonylation rate is too high, the solubility in an alkaline aqueous solution decreases. On the other hand, if the tert-butoxycarbonylation rate is too low, the dissolution inhibiting effect is small. Particularly, the tert-butoxycarbonylation rate is 30 to 6
A range of 0% is preferred. As a method for tert-butoxycarbonylating a hydrogen atom of a hydroxyl group in a poly (hydroxystyrene) derivative, a method commonly used in peptide synthesis is generally used, that is, for example, a poly (hydroxystyrene) derivative and di-tert. It can be easily produced by reacting -butyl dicarbonate. The weight average molecular weight of the poly (hydroxystyrene) derivative is preferably 10,000 or more in order to produce a resist film having high heat resistance.

Further, in order to form a highly accurate pattern, the molecular weight distribution of the resin is preferably monodisperse. For this reason, it is preferable to use a monodisperse poly (hydroxystyrene) derivative as obtained by living polymerization. Incidentally, the monodispersity means that the molecular weight distribution is Mw / Mn = 1.05 to 1.50. Here, Mw represents the weight average molecular weight of the resin, and Mn represents the number average molecular weight. In the case of living polymerization, the weight average molecular weight can be determined from the weight of the monomer and the number of moles of the initiator or the light scattering method. On the other hand, the number average molecular weight can be measured using a membrane osmometer. As a method for obtaining a monodisperse resin, (a) a method of fractionating a resin having a wide molecular weight distribution produced by a radical polymerization method, and (b) a method of obtaining a monodisperse resin from the beginning by a living polymerization method Is mentioned. Of these, it is preferable to use a living polymerization method that does not require a separation treatment. The production of the monodisperse poly (hydroxystyrene) derivative by the living polymerization method and the tert-butoxycarbonylation of the derivative can be carried out, for example, according to the method described in JP-A-6-287163.

As the dissolution inhibitor in the present invention, known general ones can be used. Examples thereof include those having a benzene ring substituted with a t-butoxycarbonyloxy group. Specific examples include various phenol compounds having hydroxyl groups t-butylcarbonylated,
Examples of the phenol compound include hydroquinone, pyrogallol, phloroglysin, 4,4'-dihydroxydiphenylmethane, 2,2'-dihydroxy-5,5'-diphenylmethane, 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenyl. Hexafluoropropane, 4,4'-dihydroxy-3,3'-dimethyl-diphenylpropane, 4,4'-dihydroxydiphenylpropane, 6,6'-dihydroxy-3,
Examples include 3,3 ′, 3′-tetramethyl-1,1-spirobiindane, and CDs used as a sulfonic acid esterification raw material in the present invention. The content of the dissolution inhibitor in the photoresist material of the present invention is preferably 7 to 40% by weight, more preferably 10 to 30% by weight. If the content of the dissolution inhibitor in the photoresist material is too large, the mechanical strength and heat resistance of the resist film are reduced. Further, if the content is too small, the dissolution inhibiting effect is small. The content of the dissolution inhibitor in the particularly preferable photoresist material is 10 to 20% by weight.

The acid generator contained in the photoresist material of the present invention is the phenolsulfonic acid ester represented by the general formula (1) of the present invention. The acid generator content is. It is preferably 5 to 15% by weight, and more preferably 0.3 to 10% by weight. If the content is too small, the sensitivity of the photoresist material cannot be improved, and if the content is too large, the mechanical strength of the resist film is lowered and the cost of the photoresist material is increased. The content of the acid generator in the particularly preferable photoresist material is 0.3 to 8% by weight.

In the photoresist material of the present invention,
If desired, it is preferable to include a sensitizer in a range that does not impair the effects of the present invention. Examples of the sensitizer include 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, mercaptooxazole, mercaptobenzoxazole, and mercaptobenzo. Mention may be made of thiazoles, benzoxazolinones, benzothiazolones, mercaptobenzimidazoles, urazoles, thiouracils, mercaptopyrimidines, imidazolones and their derivatives. At this time, the content of the sensitizer is preferably 40% by weight or less based on the acid generator,
More preferably, it is 20% by weight or less. The photoresist material of the present invention may further include compatible additives such as additional resins, plasticizers, stabilizers or developed images to improve the performance of the resist film. A conventional compound such as a coloring agent can be added.

A positive type pattern can be formed on a substrate using the photoresist material of the present invention by a known method (for example, JP-A-6-287163). That is, (1) after applying the resist material solution on the substrate, pre-baking is performed to obtain a coated substrate, (2)
The obtained coated substrate is irradiated with a high-energy ray through a photomask to generate an acid by decomposing the acid generator in the coating film, (3) heat treatment is performed, and exposure and heating of the present invention The acid generated by the decomposition of the phenol sulfonic acid ester of the general formula (1) decomposes the protective group of the dissolution inhibitor, and the dissolution inhibiting effect of the resist disappears to obtain a substrate having a latent image formed, (4) A method of forming a positive pattern by developing the latent image-bearing substrate with an aqueous alkaline solution and washing with water. In addition,
The resist material solution is a solution of the positive photoresist material of the present invention in an organic solvent, and is usually used at a concentration of 1 to 50% by weight, preferably 5 to 35% by weight. As the organic solvent used, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl isoamyl ketone, ketones such as cyclohexanone, ethylene glycol, diethylene glycol, ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol, dipropylene glycol,
Polyhydric alcohols such as propylene glycol monoacetate, dipropylene glycol monoacetate, dipropylene glycol monoacetate monomethol ether, dipropylene glycol monomethyl ether, dipropylene glycol monoacetate monopropyl ether, dipropylene glycol monobutyl ether and derivatives thereof, Tetrahydrofuran, cyclic ethers such as dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, ethoxyethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, esters such as ethyl ethoxypropionate, And mixtures thereof, but not limited to these.

[0040]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 38.9 g of benzenesulfonyl chloride was placed in a reactor equipped with a stirrer, a thermometer, a dropping funnel, and a condenser.
(0.22 mol) and 250 g of toluene were charged and stirred to obtain a uniform solution. While continuing stirring at 25 ° C., 26.8 g (0.1% of 3,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol) was obtained.
1 mol), 20 g (0.25 mol) of pyridine, and 30 g of toluene were added dropwise to the stirred solution over 2 hours. The internal temperature during dropping was such that the temperature did not exceed 30 ° C. After completion of the dropwise addition, stirring was continued for another 3 hours to allow the reaction to proceed sufficiently, and the raw material 1,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol disappeared by high performance liquid chromatography. It was confirmed. Crystals of pyridine hydrochloride were precipitated during the reaction, but with the remaining traces of pyridine and benzenesulfonyl chloride, 200 ml of dilute hydrochloric acid was added twice after the reaction, and the washing was repeated with neutral water until the drainage became neutral. Completely removed from the layer. Then, the solvent was distilled off with a rotary evaporator to obtain 54.3 g of a target sulfonic acid ester as white crystals. (Purity 99.3%, Yield 99%)

Example 2 A reactor equipped with a stirrer, a thermometer and a dropping funnel condenser was charged with 41.9 p-toluenesulfonyl chloride.
g (0.22 mol), 1,3,3-trimethyl-1-
(4-Hydroxyphenyl) -indan-6-ol 2
6.8 g (0.1 mol), pyridine 20 g (0.25
mol) and 250 g of toluene were charged, and the reaction was carried out by stirring so that the internal temperature did not exceed 30 ° C. After stirring for 3 hours to allow the reaction to proceed sufficiently, it was confirmed by high performance liquid chromatography that the raw material 1,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol had disappeared. . Crystals of pyridine hydrochloride were precipitated during the reaction, but with trace amounts of pyridine and benzenesulfonyl chloride remaining, 2 ml of dilute hydrochloric acid was added after the reaction was completed.
The organic layer was completely removed by repeating washing with neutral water until the drainage became neutral. Then, the solvent was distilled off with a rotary evaporator to obtain 57.6 g of a target sulfonic acid ester as white crystals. (Purity 99.4%, Yield 99%)

Example 3 A corresponding sulfonate ester was obtained in the same manner as in Example 1 except that benzenesulfonyl chloride was replaced with methanesulfonyl chloride. Example 4 A corresponding sulfonate ester was obtained in the same manner as in Example 1 except that benzenesulfonyl chloride was replaced with trifluoromethanesulfonyl chloride. Example 5 In place of 1,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol of Example 1, 1,3
Corresponding sulfonate ester was obtained in the same manner except that 3,3,5-tetramethyl-1- (3-methyl-4-hydroxyphenyl) -indan-6-ol was used.

Example 6 In place of 1,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol of Example 1, 1,
Corresponding sulfonic acid ester was obtained in the same manner except that 3,3, -trimethyl-5-methoxy-1- (4-hydroxyphenyl) indan-6-ol was used. Example 7 In place of 1,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol of Example 1, 1,
Corresponding sulfonic acid in the same manner except that 3,3-trimethyl-5-ishipropyl-1- (4-hydroxyphenyl) indan-6-ol was used and 4-phenoxybenzenesulfonyl chloride was used instead of benzenesulfonyl chloride. The ester was obtained.

Example 8 In place of 1,3,3-trimethyl-1- (4-hydroxyphenyl) -indan-6-ol of Example 1, 1,
The corresponding sulfonate ester was prepared in the same manner except that 3,3, -trimethyl-5-chloro-1- (4-hydroxyphenyl) indan-6-ol was used and isopropylsulfonyl chloride was used instead of benzenesulfonyl chloride. Obtained. Example 9 1-in place of the benzenesulfonyl chloride of Example 1
Corresponding sulfonate ester was obtained in the same manner except that naphthylsulfonyl chloride was used.

Example 10 A corresponding sulfonate ester was obtained in the same manner as in Example 1 except that benzenesulfonyl chloride was replaced with biphenylsulfonyl chloride. Example 11 1,3,3-Trimethyl-1- (4-hydroxyphenyl) -indan-6-ol in Example 1 was replaced by 1,
A corresponding sulfonic acid ester was obtained in the same manner except that 3,3, -trimethyl-5-allyl-1- (4-hydroxyphenyl) indan-6-ol was used. Example 12 1,3,3-Trimethyl-1- (4-hydroxyphenyl) -indan-6-ol of Example 1 was replaced by 1,
Corresponding sulfonic acid in the same manner except that 3,3, -trimethyl-5-allyl-1- (4-hydroxyphenyl) indan-6-ol was used and ethoxymethylsulfonyl chloride was used instead of benzenesulfonyl chloride. The ester was obtained. Example 13 A corresponding sulfonate ester was obtained in the same manner except that toluyloxymethylsulfonyl chloride was used in place of the benzenesulfonyl chloride of Example 1. Example 14 A corresponding sulfonate ester was obtained in the same manner as in Example 1 except that cyclohexyloxybenzenesulfonyl chloride was used instead of benzenesulfonyl chloride.

Examples 15 to 23 Using the alkali-soluble resins, dissolution inhibitors and acid generators shown in Table 1 (Table 1), resist coated substrates were produced by the following methods and evaluated by the following methods. And the result is the second
The results are shown in the table (Table 2). In addition, Mw in Table 1 indicates the molecular weight of the base resin. [Production Method of Resist Coated Substrate] A resist material solution prepared by mixing the following composition was spin-coated on a silicone substrate at 2000 rpm, and was applied on a hot plate at 85 ° C. for 1 hour.
Pre-baking was performed for a minute to produce a resist-coated substrate having a resist film thickness of 0.7 μm. Alkali-soluble resin 81 parts by weight Dissolution inhibitor 14 parts by weight Acid generator (compound of Example 1 or 2) 5 parts by weight Coating solvent (ethoxyethyl acetate) 400 parts by weight Total 500 parts by weight

[Evaluation Method of Resist Coated Substrate] The characteristics of the resist material of the present invention were measured by the following methods using the resist coated substrate manufactured by the above method. (1) Sensitivity: reduction exposure projection device N on each resist coated substrate
After exposure using SR-1505EX (manufactured by Nikon Corporation) at an excess interval of 10 mJ from 10 mJ, 100
After heating for 90 seconds at 90 ° C., then immersion development with a 2.4% by weight tetramethylammonium hydroxide aqueous solution for 65 seconds, washing for 30 seconds with water, and drying, the sensitivity is determined as appropriate exposure time (minimum exposure time required for patterning. ) Was measured. The results are expressed as values in units of 10 mJ, and the smaller the value, the shorter the exposure time and the better the sensitivity. (2) Cross-sectional shape (a) Immediately after exposure development processing: A silicon wafer obtained by exposing each resist-coated substrate with a reduction exposure projection device NSR-1505EX (manufactured by Nikon Corporation) for an optimum exposure time was heated to 100 ° C. After heating for 90 seconds, dipping and developing with a 2.4 wt% tetramethylammonium hydroxide aqueous solution for 65 seconds, washing with water for 30 seconds, and drying, the cross-sectional shape of the resist pattern is observed under a microscope, and the side surface is vertical. "○" means that the side surface is not vertical, and "x" means that the side surface is overhanging or strongly tapered. (B) 1-hour post-exposure development treatment: A silicon wafer obtained by exposing each resist-coated substrate to the optimum exposure time using a reduction exposure projection device NSR-1505EX (manufactured by Nikon Corporation) at 100 ° C. for 90 seconds. After heating, it was allowed to stand at room temperature for 1 hour, then immersion developed with a 2.4 wt% tetramethylammonium hydroxide aqueous solution for 65 seconds, washed with water for 30 seconds, and dried to obtain a cross-sectional shape of a resist pattern with a microscope. Observed, the one with vertical side faces was marked with "O", and the one with non-vertical side faces and overhang or strong taper was marked with "X".

Comparative Example 1 A resist was prepared in the same manner as in Example 15 except that tri-tert-butoxycarbonylpyrogallol was used as the acid generator in Example 15 instead of the compound in Example 1. A coated substrate was obtained, evaluated by the above method, and shown in Table 2. Comparative Example 2 Resist coating was performed in the same manner as in Example 15 except that di-tert-butoxycarbonylbisphenol A was used as the acid generator in Example 15 instead of the compound in Example 1. Substrates were obtained, evaluated by the methods described above, and shown in Table 2.

[0049]

[Table 1] tBC-HS: tert-butoxycarbonylated poly (p-hydroxystyrene) THP-HS: tetrahydropyranylated poly (p-hydroxystyrene) XL: phenol aralkyl resin HS: polyhydroxystyrene T-tBC-PG: tri-t -Butoxycarbonylpyrogallol D-tBC-BA: Di-t-butoxycarbonylbisphenol A D-tBC-HFBA: Di-t-butoxycarbonylhexafluorobisphenol A

[0050]

[Table 2] As is clear from Table 2, the photoresist material using the phenol sulfonic acid ester according to the present invention as an acid generator has a sensitivity higher than that of a photoresist material prepared using a conventionally used acid generator. And excellent resolution, and high stability over time.

[0051]

According to the present invention, it is possible to provide a positive photoresist material for high energy rays which has excellent sensitivity and resolution.

Claims (4)

[Claims] 1. A phenolsulfonic acid ester represented by the following general formula (1) (formula 1). Embedded image (In the formula, R _{1 to} R ₅ each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group which may have a substituent, an alkoxy group or an alkenyl group;
₆ represents an optionally substituted alkyl group or aryl group, and m and n represent 1 or 2. ) 2. A positive photoresist material comprising an alkali-soluble resin, a dissolution inhibitor and an acid generator,
A positive photoresist material comprising the phenolsulfonic acid ester according to claim 1 as an acid generator. 3. The positive photoresist material according to claim 2, wherein the alkali-soluble resin contains polyhydroxystyrene or a derivative thereof. 4. The positive photoresist material according to claim 3, wherein the alkali-soluble resin contains a phenol aralkyl resin or a derivative thereof.